Carburetor



Nov. 13, 1934. N. G. A. GUSTAFSSON 1,980,520

CARBURETOR Original Filed May '7, 1930 Patented Nov. 13, 1934 warren STATES resent tries FATE Aktiebolaget Jungner, Stockholm, Sweden, a corporation of Sweden Uriginal application May 7, 1930, Serial No. 450,473. Divided and this application January 26, 1933, Serial No. 653,692.

ary 26, 1930 2 Claims.

This application is a division of my copending application U. S. Serial No. 450,473, filed May 7th, 1930.

When an internal combustion engine operates under a low load, that is to say with a small throttle opening, the air velocity through the induction pipe is very small. Even if the arrangement of the fuel nozzles in the carburetor be such that fuel is supplied to the air in spite of this low velocity, the quantity of air is insufiicient to enable the said fuel to be satisfactorily atomized for which reason it passes up to the throttle in the form of large drops. This entails that the fuel-air mixture supplied to the engine is very unequally composed. again, involves uneven operation in that the distribution of the fuel to the various cylinders is irregular. When said large drops are sucked into the engine cylinder, they will of course be burned, but without any particular use, since the engine requires a homogeneous mixture of air and fuel in order to run properly. As a consequence, the economy is inferior to that which it would be if the fuelair mixture had a more homogeneous composi- 25 tion.

According to the present invention a more homogeneous mixture is attained by the combination of a butterfly valve located in the outlet of the carburetor, a fuel opening for idle running located at the engine side relatively to said butterfly valve both at the closed and the opened position of said valve, and a projection serving as a dividing member for the fuel-air mixture situated on the surface or" the valve that is directed towards the carburetor at a part thereof remote from said fuel inlet for idle running and at the opening point of the valve located nearest to the engine. The fuel from the main nozzle of the carburetor thrown against "the said surface of the valve and flowing along said surface hits the said projection when passing up to the opening between the valve and the wall of the induction pipe, whereby instead of passing through that part of said opening where the dis- 0 tance between the valve and the wall of the pipe is at maximum, it is deflected towards the sides of said projection and uniformly divided in the air.

The accompanying drawing illustrates an embodiment of the invention.

In Sweden Febru- Fig. l is an elevation of a carburetor for an internal combustion engine, the induction pipe being shown partly in section.

Fig. 2 represents a cross-section through the induction pipe.

In the drawing, 1 designates the float chamber of the carburetor and 2 the induction pipe connected thereto, in which pipe a throttle valve 3 is turnably arranged in known manner. The fuel for no-load running enters the pipe 2 through a fuel passage 4 opening above the valve 3.

In the embodiment according to Figs. 1 and 2, a projection 5 is formed by a pressing operation on the edge of the throttle valve 3 situated remote from the aforesaid fuel passage 4, and at the side of the valve directed away from the engine.

The fuel from the main nozzle (not shown) entrained by the air stream at reduced throttle opening hits the lower side of the throttle valve 3 and, following the same, has a tendency to move as far as possible along the valve and to leave the latter only at its extreme edge, that is to say, at the point where, according to the invention, the projection 5 is situated and where the distance between the valve and the wall of the induction pipe is normally the greatest. With ordinary arrangements of throttle valves an accumulation of fuel is consequently formed which, when leaving the edge of the valve, is very unsatisfactorily mixed with the air and results in the drawbacks already mentioned.

However, this is avoided by the projection 5 causing a dividing of the fuel toward the sides, whereby a better dividing of the fuel is obtained in the air stream.

What I claim is:

1. In a carburetor for internal combustion engines having an air inlet and a mixture outlet, the combination of a butterfly valve located in said outlet, 2. fuel inlet opening for idle running discharging into said outlet on the engine side of said butterfly valve both at the closed and open positions of said valve, the said valve when closed having the edge of one side thereof adjacentto said fuel inlet, the edge of the other side of said valve opposite said fuel inlet being formed with a projection on the face of said valve directed towards the air inlet when said valve is closed and with a cavity on the opposite face of said valve.

2. In a carburetor for internal combustion engines having an air inlet and a mixture outlet, the combination of a butterfly valve located in said outlet, 2. fuel inlet opening for idle running discharging into said outlet on the engine side of 5 said butterfly valve both at the closed and open positions of said valve, and a projection on the face of said valve directed towards the air inlet NILS GUSTAF ALBERT GUSTAFSSON. 

